c#_生成图片式验证码

废话不多说直接上代码。

     class Check_Code
     {
         /// <summary>
         /// 生成随机验证码数字+字母
         /// </summary>
         /// <param name="codelen">验证码长度</param>
         /// <returns>返回验证码</returns>
         public static string MakeCode(int codelen)
         {
             if (codelen < )
             {
                 return string.Empty;
             }
             int number;
             StringBuilder strCheckCode = new StringBuilder();
             Random random = new Random();
             for (int index = ; index < codelen; index++)
             {
                 number = random.Next();
                 if (number %  == )
                 {
                     strCheckCode.Append((char)('' + (char)(number % )));//生成随机数字
                 }
                 else
                 {
                     strCheckCode.Append((char)('A' + (char)(number % )));//生成随机字母
                 }
             }
             return strCheckCode.ToString();
         }
         public static MemoryStream CheckCodeImage(string CheckCode)
         {
             if (string.IsNullOrEmpty(CheckCode))
             {
                 return null;
             }
             Bitmap image = new Bitmap((int)Math.Ceiling((CheckCode.Length * 12.5)), );
             Graphics graphic = Graphics.FromImage(image);//创建一个验证码图片
             try
             {
                 Random random = new Random();
                 graphic.Clear(Color.White);
                 int x1 = , y1 = , x2 = , y2 = ;
                 for (int index = ; index < ; index++)
                 {
                     x1 = random.Next(image.Width);
                     x2 = random.Next(image.Width);
                     y1 = random.Next(image.Height);
                     y2 = random.Next(image.Height);
                     graphic.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
                 }
                 Font font = new Font("Arial", , (FontStyle.Bold | FontStyle.Italic));//Font设置字体，字号，字形
                 //设置图形渐变色的起始颜色与终止颜色，渐变角度
                 LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(, , image.Width, image.Height), Color.Red, Color.DarkRed, 1.2f, true);
                 graphic.DrawString(CheckCode, font, brush, , );
                 int X = ; int Y = ;
                 //绘制图片的前景噪点
                 for (int i = ; i < ; i++)
                 {
                     X = random.Next(image.Width);
                     Y = random.Next(image.Height);
                     image.SetPixel(X, Y, Color.FromArgb(random.Next()));
                 }
                 //画图片的边框线
                 graphic.DrawRectangle(new Pen(Color.Silver), , , image.Width - , image.Height - );
                 //将图片保存为stream流返回
                 MemoryStream ms = new MemoryStream();
                 image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
                 return ms;
             }
             finally
             {
                 graphic.Dispose();
                 image.Dispose();
             }
         }
     }

生成验证码图片，需要先生成验证码，再将验证码处理为图片。

转载引用黎木博客-https://www.cnblogs.com/running-mydream/p/4071528.html